1. Field of the Invention
The present invention relates to a metal gasket having a stainless steel backing material and a sealing rubber film on its surface.
2. Description of the Related Art
A main body of an engine for use in a small watercraft can be constructed by, for example, assembling a plurality of case members such as a cylinder head and a cylinder body. A metal gasket for preventing infiltration of coolant is provided on mating surfaces of the cylinder head and the cylinder body. A conventional metal gasket is made up of a stainless steel plate. A composite film having a chromium compound, phosphoric acid and silica as its main components is formed on a surface of the stainless steel plate, and a rubber layer made of a nitrile rubber composite is coated on a surface of the composite film.